The present invention relates generally to electrical stimulators for biological tissue and more particularly to electrical stimulators for having remote control.
Electrical stimulators providing an electrical stimulus signal are useful for biological tissue. One significant use for electrical stimulators of this type is for transcutaneous electrical nerve stimulation (TENS) which generate carefully controlled electrical stimulus signals which are delivered via suitable electrodes through a patients' skin to underlying biological tissue. The electrical stimulus signals are utilized masking pain signals, for example, the sensation of pain felt by a patient after surgery. Because the patient's response to transcutaneous electrical nerve stimulation (TENS) very significantly, a wide range of electrical stimulus signals must be provided. A second use of electrical stimulators is for neuromuscular stimulation (NMS) in order to initiate or control muscular contraction in a patient. Since a wide variety of muscular actions are available again a wide variety of electrical stimulus signals must be provided.
Electrical stimulators may deliver electrical stimulus signals which may be a pulsatile signal. Such pulsatile signals can originate from differing modes of operation of the electrical stimulator.
In a transcutaneous electrical nerve stimulation (TENS) mode, electrical stimulators deliver an electrical stimulus signal which is pulsatile according to predetermined stimulus parameters such as pulse amplitude, pulse duration and pulse frequency or repetition rate. While such stimulus parameters typically may be predetermined or specified as, for example, from an external programmer, patient (user) response to such parameters can vary significantly. Thus, it is desirable to vary, or alter such stimulus parameters on a real-time basis so that the electrical stimulus signal generated may be adjusted to the individual patients' needs and comfort.
In a neuromuscular stimulation (NMS) mode, an electrical stimulator may deliver an electrical stimulus signal consisting of a pulse train with a predetermined sequence of stimulation parameters such as pulse amplitude, pulse duration and pulse frequency or repetition rate. While the pulse train may be specified by predetermined stimulus parameters, it is desirable to have the timing of the application of such a pulse train in the electrical stimulus signal under real-time user (patient) control.